A method of the type mentioned above is known from DE 100 27 159 A1, where methanol vapor is converted into a dimethylether (DME) containing vapor mixture in a first catalyst from which a propylene-containing first product mixture is created based on a form selective Zeolite catalyst. From this, a 99.5 percent by volume propylene-containing product stream is extracted through a separation system while the remaining products are carried separately or can also be partly recirculated again in the form-selective Zeolite catalyst for renewed conversion.
It is unfavorable that in the most recent background art, recycling of the remaining products for renewed conversion in the Zeolite catalyst is only ineffectively possible.
Therefore, the basic objective of the invention is to continue developing a method and a device of the type mentioned in the beginning in such a way that the recycling of the remaining products in the manufacturing of lower olefins can be carried out effectively.